The Connecticut Democrat called it a shameful record that shows an urgent need for immediate attention to safety and reliability.

There were 139 violations since 2004, Blumenthal said, citing data he received from the Federal Railroad Administration. He said per 100 miles of track, Metro-North had five times the number of safety defects than any other commuter railroad in the country. A Metro-North spokeswoman said earlier this month that Metro-North generally does better during federal inspections than most railroads.

“While not every reported defect is a serious safety threat, the magnitude of violations is deeply troubling,” Blumenthal said. “The pertinence and practical importance of these defects is staggeringly clear. One of the most serious failings – broken or cracked joint bars, loose rail braces and missing bolts – almost certainly caused the Bridgeport derailment and collision, which resulted in more than 70 injuries and paralyzed the regional economy.”

He criticized the FRA for not imposing steeper fines or stepping up its enforcement until last year despite a spike in violations five years earlier.

“These fines are shocking in sheer frequency, but what is frankly incomprehensible and unacceptable is the Federal Railroad Administration’s inexplicable failure to do its job and demand changes and improvements as these defects and fines mounted,” Blumenthal said.

An investigation by the Stamford Advocate concluded that fines imposed on Metro-North are so small that they fail to act a deterrent, WCBS 880’s Fran Schneidau reported. For example, the railroad was fined a mere $5,000 following the death of a seasoned track worker last May.

Blumenthal said hearings will be held with an eye to strengthening penalties.

“I’m going to be asking both the railroad and the federal agency why there were so many violations so frequently, and yet such small penalties that failed to serve as a deterrent,” Blumenthal told WCBS 880’s Fran Schneidau.

Metro-North spokeswoman Marjorie Anders points out the fines are set by law, and not imposed at the discretion of the railroad, Schneidau reported.

A message left Friday morning with the FRA seeking comment wasn’t immediately returned.

“Safety was not the top priority,” he said. “It must be, and it will be. Every problem I have seen here can be fixed and will be fixed.” He said “aggressive actions” were already underway, including a program that would allow workers to make confidential calls raising safety issues.

Anders said the railroad has made tremendous strides in improving its safety culture in the wake of the two derailments.

Metro-North did a thorough inspection of its tracks and other infrastructure and tightened safeguards on when tracks are put back into service, Anders said. It is implementing other improvements such as anonymous reporting of near-accidents, she added.